Description

Several readers have asked for an inexpensive solar controller kit for charging 12 volt lead-acid batteries. The specifications for this project (given by one of the readers) were to control the charging of lead-acid batteries up to 12 amps using solar cells. He wanted the unit to start charging if the battery voltage went below 13.5 volts, and then turn the charging off when it reached 14.25 volts.

This project is very inexpensive and fits onto a heatsink that is mountable. Since the voltage is low, there is no danger of shock. It is simple to build, ideal for the novice, and no special tools are needed other than a soldering iron and a 9/64" drill.

Kit Includes:

1 – 0.33 µF Capacitor

1 – .1 µF Capacitor

1 – Eight-pin Socket

1 – PIC12F675-I/P (Programmed)

1 – Bi-colored LED

1 – 5 volt Voltage Regulator

1 – P power MOSFET IFR 5305

1 – N MOSFET 2N7000

2 – 18.2K ohm 1/4W 1% Resistors

2 – 909 ohm 1/4W 1% Resistors

1 – 100K ohm 1/6W 5% Resistor

1 – 220 ohm 1/6W 5% Resistor

1 – Heatsink

2 – Nylon 1/4" Spacers

1 – 6-32 3/8" Nylon Screw

1 – 6-32 Nylon Nut

2 – 6-32 5/8" Screws

1 – Thermal Pad

1 – Black 18 gauge stranded 1 ft

1 – Red 18 gauge stranded 1 ft

1 – Diode Schottky 45V 12A

1 – Printed Circuit Board

Download the Template, Tips, PCB, Schematic, and Code at the article link above.